QUANTITATION OF HERPES-SIMPLEX VIRUS TYPE-1 DNA IN CELLS OF CEREBROSPINAL-FLUID OF PATIENTS WITH HERPES-SIMPLEX VIRUS ENCEPHALITIS

We used a nested polymerase chain reaction assay to quantitate the num ber of viral copies in cells of CSF of eight patients with herpes simp lex virus encephalitis (HSVE). The viral load was monitored in serial CSF samples during the course of disease and correlated to clinical sy mptoms, radiologic manifestations, efficacy of acyclovir treatment, an d overall clinical outcome. Before treatment, HSV type 1 (HSV-1) copie s were detected at a mean value of 1,786/10(5) (range, 5 to 8,533/10(5 ) cells; median, 81/10(5) cells). During therapy, HSV-1 DNA decreased gradually to a mean value of 6 copies/10(5) cells (range, 0 to 33 copi es/10(5) cells; median, 0 copies/10(5) cells) within 6 to 21 days and disappeared or was barely detectable before treatment completion in mo st cases. The HSV-1 burden in the CSF did not clearly correlate with t he severity of clinical signs or the degree of cranial imaging finding s and overall outcome. Quantitation of HSV-1 copies allows rapid and r eliable monitoring of antiviral therapy. The absence of a clear correl ation between viral load in the CSF and morbidity may suggest a role f or indirect mechanisms of brain injury in HSVE.